Adrenal gland volume determination by computed tomography and magnetic resonance imaging in normal subjects

To compare the usefulness of computed tomography (CT) and magnetic resonance imaging (MRI) for the quantitative determination of adrenal gland size in human subjects, adrenal gland volumes were determined by both techniques in five female and five male, normal, nonstressed adult volunteers. Mean left and right adrenal volumes were slightly larger by CT, and the left adrenal volume was slightly larger than the right by both imaging techniques. Volume determinations by CT and MRI correlated +0.85 and +0.82 for the left and right glands, respectively. Body surface area was highly correlated, and sex moderately correlated, with left and right adrenal volumes by both techniques. Both CT and MRI somewhat overestimated the known volumes of a set of phantoms, CT by an average of 42% and MRI by an average of 20%. The results of this initial study suggest that MRI holds promise as a technique for in vivo adrenal gland measurements, and that the influence of both body surface area and sex should be considered in comparative studies of adrenal size.